Form for concrete.



J. R. SELFHIDGE.

FORM FOR CONCRETE.

APPLICATION FILEDJULY6,1915,

Patented Dec. 7, MN5.

2 SHEETS--SHEET l.

WITNESSES J. R. SELFRIDGE.

FORM FOR CONCRETE.

APPLlcATIoN r|LED1uLY6,1915.

LLP.. lzlented Dec. 7, 1915.

2 SHEETS-SHEET 2.

IN V EN TOR.

WITNESSES: ua' SELF'R/GE f um -BYv-Qm 4 /Q A TTORNE YS.

` UNrrED srarns PATENT onirica.'

JAMES R. SELFRIDGE, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR T0 SELFRIDGEHOLDING COMPANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OFCALIFORNIA.

FORM FOR CONCRETE.

Application led July 6, 1915.

To all whom t may concern Be it known that I, JAMES R. SELFRIDGE, acitizen of the United States, and a resident of the city and county ofSan Francisco,

State of California, have invented a certain new and useful Form forConcrete, of which ;he following is a specification.

The invention relates to forms for concrete building construction andparticularly to forms for building columns.

An object of the invention is to provide a`cheap and eflicient form foruse in concrete building construction.

Another object of the invention is to provide a system of formscomprising spirally wound paper tubes.

The invention possesses other advantageous features, which, with theforegoing, will be set forth at length in the following description,where I shall outline in full that form of the invention which l haveselected for illustration in the drawings accompanying and forming partof the present specification.

The drawings and specification disclose one form of embodiment of myinvention, but it is to be understood that the invention maybe embodiedin other forms without departing froin the .spirit of the invention, asexpressed in the appendedclaims.

Referring to said drawings: Figure 1 is a horizontal section'of aportion of a concrete building taken above a floor.' Fig. 2 is avertical section of the section shown in Fig. 1, 4taken on the line A-A.Fig. 3 is a vertical section taken on the line B-B Fig. 1. Fig. 4c is avertical section taken on the line GC Fig. 1.

My invention contemplates the use of spirally'wound paper tube as theform for concrete columns and a system of form support whereby 4thepaper tubes may be used.

llt further contemplates a system of forms in which both floor forms andcolumn forms consist of spirally wound paper tube. The floor is formedwith the usual concrete beams and girders intersecting at the top of thecolumn. A y

ln accordance with my invention, a spirally woundpaper tube 2 isemployed as the column form and extends from one floor to theintersection of the beam and girder of the Hoor above. Spirally woundpaper tube, on account of its construction, forms a rigid, light andcheap mold, which, when Specification of Letters Patent.

Patented Dec. 7, 1915.

Serial No. 38,094.

lcould not retain or support the concrete.

The forms 5 for the main transverse and longitudinal concrete floorbeams 3-4 are formed of wood and are suitably supported from the floorbelow by means of posts 6 or other suitable structures, the paper tubecolumn forms 2 not being of suihcient strength to support the weight ofthe freshly poured concrete floor. The floor forms between the beams 3consist of a plurality,` of arched segments' of spirally wound tube 7spaced apart to form the necessar beams 8. The segments are supported aong their edges by boards 9 which are in turn supported from the floorbelow by the posts 6.

The spirally wound paper tubes 2 which form the column forms extendupward to the soiits of the beams 3-4 and the forms 5 are provided withopenings at the intersection of the beams so that the column and floorconcrete form a monolithic mass. Reinforcing bars or rods 12 extend fromthe interior of the form 2 through the floor, up into the column formabove, and reinforcing rods or bars 13 extend from the form 2 out intothe beams 3 4. After the concrete has been poured and set, thesupporting frames and the paper tubes may be removed.

This construction provides a simple and cheap construction of concreteforms and on account of the low cost of the paper tube is entirelypractical. The forms are cheap and the use of a fresh form for eachcolumn will not entail any greater expense than the use of wood, whichis used repeatedly. A circular column is more eicient than a column alla1,163,376

prising floor forms, means for supporting said :door forms and spirallyWound paper tube column forms cooperating with said floor forms.

2. In concrete construction, floor forms, supports for said loor formsextending from a floor below and spirally Wound paper tube column formsextending from said floor to said floor forms.

3. In concrete construction, the combination with.v a spirally Woundpaper tube column form, of Wooden forms for intersecting beams of thefoor above having an aperture therein at their intersection registeringWith said column Jform and means for supporting said beam forms.

4. In concrete construction, a spiraily Wound paper tube column form anda floor form independently supported above said column form.

5. In concrete construction, the combination of a floor form formed ofse ments of spirally wound paper tube space apart transversely, meansfor supporting said segments and a column form of spirally Wound papertube.

In testimony whereof, I have hereunto set my hand at San Francisco,California, this 21st day of June 1915.

JAMES R. SELFRIDGE.

In presence of- H. G. IRos'r.

